1,721,173 research outputs found
Microscopy of defects in semiconductors
Full text linkIn this chapter, the authors discuss microscopy techniques that can be useful in addressing defects in semiconductors. They focus on three main families: scanning probe microscopy, scanning electron microscopy and transmission electron microscopy. They first address the basic principles of the selected microscopy techniques In discussions of image formation, they elucidate the mechanisms by which defects are typically imaged in each technique. Then, in the latter part of the chapter, they describe some key examples of the application of microscopy to semiconductor materials, addressing both point and extended defects and both two-dimensional (2D) and three-dimensional (3D) materials
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Probabilistisen seismisen hasardilaskennan herkkyystarkastelu Hanhikiven laitospaikalla
Full text linkNuclear energy company Fennovoima is planning to construct a nuclear power plant (NPP) on the Hanhikivi peninsula in Pyhäjoki. Prior to construction, the Hanhikivi 1 NPP shall be designed to withstand seismic hazards. In the Finnish nuclear industry, the assessment of seismic risks begins with a probabilistic seismic hazard assessment (PSHA). The aim of this work is to review the most significant parameters in the logic tree of Hanhikivi 1 PSHA. The scope of the thesis includes examining approaches to evaluate the maximum magnitude mmax and involving two new ground motion prediction equations (GMPEs) in the PSHA. We corrected the weights calculated by applying the Kijko approach in the current PSHA and demonstrated the shortcomings of the weight assessment method. We also attempted to derive the mmax directly from the Kijko approach, but the calculated value was deemed unreasonably low. The first included GMPE was the modified G16 GMPE recently developed to the Fennoscandian conditions. The second GMPE was derived from the Dahle function by the author. The modified Dahle GMPE was calibrated to Fennoscandia in the applicability range of Rhyp <= 200 km and M_w <= 6,5. A comparison to the measured data and the other GMPEs suggests that the modified Dahle GMPE underestimates ground motion for M_w < 5,0 in near distance (Rhyp <= 10 km). Therefore, we included the modified Dahle GMPE in the logic tree with a relatively small weight factor. We ran the seismic hazard analyses on EZ-FRISK and compiled the ground response spectra (GRS) following the logic tree. The GRS were compiled for a range of annual frequencies of exceedance (AFE = 10-4 a-1 - 10-8 a-1), but the thesis only discusses the results at AFE = 10-5 a-1 due to its significance in nuclear safety. We compared the computed GRS with the current GRS of the Hanhikivi 1 site. Including the new GMPEs alleviated the unphysical features in the current Hanhikivi 1 GRS caused by the drastically different ranges of the Pezeshk and Fennoscandian GMPEs. In summary, we improved our understanding of the PSHA sensitivity to the mmax and GMPE parameters, but our work also brought up and highlighted issues regarding them.Energiayhtiö Fennovoima suunnittelee ydinvoimalaitoksen rakentamista Hanhikivenniemelle Pyhäjoella. Rakentamislupaa varten voimalaitos täytyy suunnitella kestämään seismisiä hasardeja. Suomessa seismisten riskien arviointiin käytetään todennäköisyysperusteista seismisen hasardin arviointia (PSHA). Työssä on tarkoituksena tarkastella Hanhikivi 1 -laitoksen PSHA:n logiikkapuun merkittävimpien parametrien laskentaa. Lisäksi työssä käydään läpi tapoja maksimimagnitudin (mmax) määrittämiseen ja lisätään kaksi uutta maanvaimennusyhtälöä (GMPE) logiikkapuuhun. Työssä korjattiin tämänhetkisen PSHA:n väärinlasketut Kijko-menetelmään pohjautuvat painokertoimet ja demonstroitiin painotusten laskemistavan heikkouksia. Maksimimagnitudi yritettiin määrittää myös suoraan Kijko-menetelmästä, mutta tulos oli epäuskottavan pieni. Logiikkapuun ensimmäinen uusi GMPE on vastikään Fennoskandian oloihin kehitelty muunnettu G16 GMPE. Toinen GMPE johdettiin Dahle-funktiosta osana diplomityötä. Muunnettu Dahle GMPE kalibroitiin Fennoskandian oloihin, jossa sen on arvioitu soveltuvan Rhyp <= 200 km ja Mw <= 6,5 välillä. Muunnettua Dahle GMPE:tä vertailtiin mittauksiin ja muihin GMPE:ihin, minkä perusteella GMPE vaikuttaa aliarvioivan maanliikettä matalilla magnitudeilla Mw < 5,0 lähietäisyydellä (Rhyp <= 10 km). Muunnettu Dahle GMPE sisällytettiin silti logiikkapuuhun, mutta pienemmällä painokertoimella. Seismiset hasardianalyysit ajettiin EZ-FRISK-ohjelmistolla, ja hasardianalyyseistä koostettiin logiikkapuuta vastaavat maavastespektrit. Maavastespektrit koostettiin usealle esiintymistaajuudelle (AFE = 10-4 a-1 - 10-8 a-1), mutta työssä keskitytään esiintymistaajuuteen AFE = 10-5 a-1 taajuuden turvallisuusmerkityksen vuoksi. Vertasimme laskettua maavastespektriä nykyiseen Hanhikivi 1 laitoksen maavastespektriin. Uusien GMPE:iden läsnäolo vähensi nykyisessä Hanhikivi 1 -maavastespektrissä havaittuja epäfysikaalisia piirteitä. Yhteenvetona työ paransi ymmärrystä PSHA:n herkkyydstä mmax- ja GMPE-parametreille, mutta työssä tuotiin esiin myös ongelmat parametreihin liittyen
Development of the Periodic Inspection Programme According to the New Regulatory Guides on Nuclear Safety
Full text linkYdinenergian käyttö on tarkasti säädeltyä toimintaa. Suomessa sen käyttöä ja valvontaa säädellään kotimaisella lainsäädännöllä ja yksityiskohtaisilla turvallisuusmääräyksillä. Ydinenergian käytön valvonnasta vastaavana viranomaisena Suomessa toimii Säteilyturvakeskus (STUK).
Yhtenä STUKin tehtävänä on valvoa ydinvoimalaitosten käyttöä. Valvonnalla STUK pyrkii varmentumaan siitä, että luvanhaltijat käyttävät laitoksiaan viranomaismääräysten mukaisesti. Valvontatyössä käytön tarkastusohjelman tarkastukset toimivat yhtenä merkittävänä havaintojen lähteenä.
Tässä työssä perehdytään ydinturvallisuusvalvontaan valvovan viranomaisen näkökulmasta. Työn tavoitteena on kehittää käytön tarkastusohjelmaa uusien ydinvoimalaitosohjeiden pohjalta. Lisäksi tavoitteena on kehittää vaatimuslähtöistä valvontatapaa, mikä tarkoittaa sitä, että ohjelman tarkastukset olisivat selkeämmin lähtöisin viranomaisvaatimuksista.
Kaikki työssä esitetyt ehdotukset ja arviot ovat diplomityöntekijän omia näkemyksiä eivätkä näin edusta STUKin virallista kantaa.The use of nuclear energy is strictly regulated activity. In Finland, the use and oversight of nuclear energy is regulated by national legislation and by detailed safety requirements. Radiation and Nuclear Safety Authority (STUK) is responsible for the supervision of the use of nuclear energy in Finland.
One of STUK's tasks is to oversee the operation of nuclear power plant units. By the means of this oversight STUK aims to get a high level of assurance that the licensees operate their units in compliance with the regulatory requirements. The inspections of the Periodic Inspection Programme act as significant source of findings in this work.
In this thesis we will get acquainted with nuclear safety oversight from the point of view of the regulatory body. The objective of this thesis is to develop the Periodic Inspection Programme according to the new Regulatory Guides on nuclear safety. Furthermore, the aim is to develop requirement-based inspection method. This means that the inspections of the program would more clearly originate from the regulatory requirements.
The suggestions and estimates presented in this thesis are the personal opinions of the author and, thus, do not represent the official position of the Radiation and Nuclear Safety Authority
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